On Tue, Apr 15, 2025 at 09:15:19AM -0700, Kees Cook wrote:
> Avoid double-copying of string literals. Use a "const char *" for each
> string instead of copying from .rodata into stack and then into the skb.
> We can go directly from .rodata to the skb.
> 
> This also works around a Clang bug (that has since been fixed[1]).
> 
> Reported-by: kernel test robot <[email protected]>
> Closes: 
> https://lore.kernel.org/oe-kbuild-all/[email protected]/
> Fixes: ab4e4380d4e1 ("Bluetooth: Add vhci devcoredump support")
> Link: 
> https://github.com/llvm/llvm-project/commit/ea2e66aa8b6e363b89df66dc44275a0d7ecd70ce
>  [1]
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>

Reviewed-by: Nathan Chancellor <[email protected]>

> ---
> Cc: Marcel Holtmann <[email protected]>
> Cc: Luiz Augusto von Dentz <[email protected]>
> Cc: Josh Poimboeuf <[email protected]>
> Cc: Nathan Chancellor <[email protected]>
> Cc: Peter Zijlstra <[email protected]>
> Cc: [email protected]
> ---
>  drivers/bluetooth/hci_vhci.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/bluetooth/hci_vhci.c b/drivers/bluetooth/hci_vhci.c
> index 7651321d351c..9ac22e4a070b 100644
> --- a/drivers/bluetooth/hci_vhci.c
> +++ b/drivers/bluetooth/hci_vhci.c
> @@ -289,18 +289,18 @@ static void vhci_coredump(struct hci_dev *hdev)
>  
>  static void vhci_coredump_hdr(struct hci_dev *hdev, struct sk_buff *skb)
>  {
> -     char buf[80];
> +     const char *buf;
>  
> -     snprintf(buf, sizeof(buf), "Controller Name: vhci_ctrl\n");
> +     buf = "Controller Name: vhci_ctrl\n";
>       skb_put_data(skb, buf, strlen(buf));
>  
> -     snprintf(buf, sizeof(buf), "Firmware Version: vhci_fw\n");
> +     buf = "Firmware Version: vhci_fw\n";
>       skb_put_data(skb, buf, strlen(buf));
>  
> -     snprintf(buf, sizeof(buf), "Driver: vhci_drv\n");
> +     buf = "Driver: vhci_drv\n";
>       skb_put_data(skb, buf, strlen(buf));
>  
> -     snprintf(buf, sizeof(buf), "Vendor: vhci\n");
> +     buf = "Vendor: vhci\n";
>       skb_put_data(skb, buf, strlen(buf));
>  }
>  
> -- 
> 2.34.1
> 

Reply via email to